Conventional hydraulic systems that are used to drive mechanical systems in down-hole applications in wells, such as oil or gas wells, mainly employ two or more hydraulic solenoid valves to orient the flow in the hydraulic lines. These conventional systems, however, do not have a very good reliability due to oil pollution and/or internal leaks. In addition, the hydraulic oil flow rate can be poor through the solenoid valves used in wireline tools due to the small passageways used in these systems. This poor rate of flow increases the time that it takes the hydraulic systems to drive the mechanical systems in the well.
In typical wireline tools which use hydraulic circuits to move a mechanical system, one of the important factors that affects the success of the job is the time spent activating the hydraulic system. Frequent changes in position, and the setting and retracting of hydraulic pistons in such a system lead to an increase in the drilling time that is lost during the completion of these procedures.
The simplicity or complexity of the hydraulic systems used in a well is a factor of reliability as well. This invention discloses a hydraulic manifold pump that can set and retract a piston in an actuator by hydraulic means using a 2-way flow of hydraulic fluid, without the use of solenoid valves. One of the advantages of the current invention is that the hydraulic flow mechanisms are more simple, and thus more efficient and reliable. This simplicity results in the minimum amount of drilling time lost as a result of the activation of the hydraulic system.
In addition, using a faster hydraulic system to drive the kinematics in a wireline tool offers many advantages in terms of the reduction in cost-of-logging. This is accomplished by less drilling time being lost when the hydraulic mechanism is set and retracted, and by a reduction in the electrical power needed to run the tool as the tool needs fewer electrical components in order to drive the hydraulic high pressure portion of the pump system and thus also needs less electricity in order to function.